Valve Sealing Requirements And Other Requirements

sealing requirements

The sealing performance of the valve refers to the ability of each sealing part of the valve to prevent the leakage of the medium, which is the most important technical performance index of the valve. There are three sealing parts of the valve: the contact between the opening and closing parts and the two sealing surfaces of the valve seat; the cooperation between the packing and the valve stem and the stuffing box; the connection between the valve body and the valve cover. The leakage in the former part is called internal leakage, which is commonly referred to as lax closure, which will affect the ability of the valve to cut off the medium. For shut-off valves, internal leakage is not allowed. The leakage in the latter two places is called external leakage, that is, the medium leaks from the inside of the valve to the outside of the valve. External leakage will cause material loss, pollute the environment, and even cause accidents in severe cases. For flammable, explosive, toxic or radioactive media, leakage is not allowed, so the valve must have reliable sealing performance.

other requirements

1. Purge the assembled valve with nitrogen for at least 1 minute.

2. The air tightness test must be performed with pure nitrogen.

3. Encapsulate after passing the air tightness test, seal with a clean polyethylene cap, soak the polyethylene cap with an organic solvent before use, and wipe it clean.

4. Then seal it with a vacuum bag.

5. Final packing.

6. Measures should be taken to ensure that the package is not damaged during transportation.